2,4,6-tri-tertiary-amyl phenol



Patented 8, 19 4.l-

p I 2,248,829 I UNITED s'rA'rEs PATENT OFFICE 2 248.82 1 zao-rai-raanaar-mn PHENOL Donald B. Stevens; Swissvale, and William A. Gruie, Wilkinaburg, Pa., assignors to Gull Oil Corporation, Pittsburgh, Pa., a corporation or rom No Original application April 12. 1931,

891111 100.1385. Divided and this applicatic-January 1s. 1m, Serial No. 251,283

1 Claim.

This invention relates'to tri-alkylated monohydroxy phenols, and more particularly to 2,4,8,- tri-tertiary-amyl-phenol, a compound which is soluble in oil and insoluble in water and. in dilute aqueous alkali solution, and which possesses the property of inhibiting oxidational changes in petroleum hydrocarbon products when added thereto in relatively small amounts:

all as more fully hereinaiterset forth and asclaimed. s

This application is a division of'our copending applicationfor United States Letters Patent Serial No. 136,504, filed April 12, 1937, now matured into Patent No. $202,877, issued June 4, 1940.

In our earlier illed applications Serial No. 649,670, filed December 30,1932, and Serial No. 702,258, filed December 13, 1933, now U. 8. Patent No. 2,061,111, we have described and claimed the manufacture of antioxidants and the addition thereof to motor fuels, which antioxidants tiary-amyl-phenol which we have synthesized in substantially pure form. y

We have discovered that by alkyiating phenol with iso-amylene or tri-methyl-ethylene until no more tri-methyl-ethylene reacts with the phenol, I

we can produce 2,4,6-tri-tertiary-amyl-phenol, a compound which is soluble in ,oil, and insoluble in dilute-aqueous alkali solution. -We have discovered also that this compound possesses good antioxidant properties and when added to petroleum oil products such as gasoline, lubricating oils,

transformer oils, turbine oils and the like, in

relatively small amounts it stabilizes these materials against oxidational changes. In preparing 2,4,6-tri-tertiary-amyl-phenol, iso-amylene, either alone or in admixture with other hydrocarbons, may be used in alkylating the phenol. Cracked gasoline as normally proare obtained by treating low-boiling cracked 'distillates, such as cracked gasoline containing olefins, such as propylene and butylene, with' arylhydroxy compounds'such as phenol, cresols or xylenols at-a relatively low temperature in the presence of an acid condensing agent, or at a relatively high temperature in the absenceof duced, and the heavier of the hydrocarbons usually iound as vapors n cracking-still gases contain varying quantities of iso-amylene as well as higher olefins, and may be used as starting materials. on the other hand, the iso-amylene may be used in isolated form or in admixture with other closely related olefins or parafllns.

' It will be readily understood that when it is dean acid condensing agent. In our copending' application Serial No. 110,014, filed November 9,

1936, which is a division of application Serial No.

-droxy phenols having in-a position ortho to the hydroxy group at least one alkyl substitution.

group having three or more carbon atoms, e. g., a propyl,- butyl, amyl or high alkyl group, the remaining alkyl groups being similar or different, for example, methyl, ethyl or higher alkyl groups, which compounds are soluble in oil and insoluble in dilute aqueous alkali solution and in water.

The present application is concerned with one of this newly discovered class, disclosed in said application Serial No. 136,504, namely, 2,4,6 tri-tersired to prepare 2,4,6-tri-tertiary-amyl-phenol, free orsubstantially free from other compounds, the raw material should not comprise mixtures oi! oleflns or mixtures of phenols, except in those cases in which the natures of the individual products will permit easy isolation and separation after alkylation. As to mixtures of isoamylene and parafflns such as pentane, the presence of the parafiln has no effect on the operation other than to reduce the concentration of the iso-amylene; thepentane does not enter into the reaction with the phenol. 1

In general the methods set forth in our prior applications referred to hereinabove may be employed in preparation of 2,4,6-tri-tertiary-amylphenol,-w ith due regard to the selection 01' the raw materials. Thus, at temperatures up to F. or thereabouts, and under atmospheric or moderately elevated pressures, the usual condensing 'agents are employed, including sulfuric acid, phosphoric acid, anhydrous aluminum chloride, boron tri-fiuoride, ferric chloride, hydrogen chloride and the like. Sulfuric acid is ordinarily most satisfactory by reasonoi its efllciency and cheapness. The amount of acid condensing agent required is relatively small with respect to the amount of phenol; in some instances the amount of acid condensing agent required is as little as 1 percent of the phenol or less, .being'in such instances present in catalytic amounts. In using sulfuric acid as the condensing agent, and when it is desired to utilize the isoamylene emciently, it is usually better to employ the-acid in an amount equal to not less than about 3.0 percent of the phenol. More than percent of the condensing agent, based on amount of phenol is not ordinarily worth while. At higher temperatures and pressures, for example from about 400 to 575 F. or higher, and 1,000 pounds per square inch or somewhat higher, condensing agents are sometimes unnecessary and may 'be omitted. The

temperatures should not be so highas to cause decomposition of the phenol. It is ordinarily advantageous to avoid temperatures and pressures so high that the product obtained will predominate in polymerized iso-amylene, the formation of which is enhanced by heat and pressure.

The reaction involves no special dlfiiculties, the

reacting ingredients being simply contacted in the usual manner either continuously or in batch operation. After completion of the reaction the products are usually washed with an aqueous solution of caustic soda or other equivalent alkali, the strength of the washing solution being preferably not over per cent. This washing operation removes any remaining acid condensing agent and also removes all alkali soluble material such as any unreacted phenol, as well as alkylatlon products in which the alkylation has not proceeded to the point desired. Water washin may also be resorted to wherever desired. The washed product may then be distilled under ordinary pressure or under vacuum and recrystallized in the usual manner to separate the by-products and obtain substantially pure 2,4,6-tri-tertiaryamyl-phenol.

In general we find it advantageous to employ ordinary concentrated sulfuric acid in amounts corresponding to about from 3 to 5 per cent by weight of the phenol; with this concentration the rate of condensation is sumciently high, while with higher amounts of acid the tendency toward polymerization of the iso-amylene is increased.

jOr proportion of 2,4,6-tri-tertiary-amyl-phenol weight of commercial sulfuric acid were introduced into the vessel and the mixtur was brought to and maintained at about 70 C., at which temperature the phenolic mixture was liquid. Warm tri-methyl-ethylene was then slowly admitted as-a gas through the gas inlet, with agitation, the introduction of the gas being continued until the volume of the reaction products and the character and amount of the exit gases indicated completion of the reaction. The rose-- tion mixture was weathered by blowing it with an inert gasto volatilize and carry off any residamber colored syrupy liquid which upon separa- We also find it advantageous in obtaining a ma-- inthe total products of the reaction to maintain rials. f

The following example will serve to illustrate our invention.

The apparatus employed consisted of a cylindrical reaction vessel having a gas inlet at the bottom and a gas outlet at the top, agitating means suitable for finely dividing the incoming gas, and a heating or cooling coil. The gas inlet was so arranged with respect to the agitating means that the incoming gases were finely divided immediately upon coming into contact with the liquid in the reaction vessel; The reaction was performed under atmospheric pressure; 500

parts by weight of pure phenol and 25 parts by tion and distillation at '7 mm. pressure gave a constant boiling fraction. This fraction boiled at 136 C. under the reduced pressure noted and was found to be a colorless syrupy liquid having a specific gravity of 0.9258 and a refractive index of 1.4955. When 0.04 gram by weight of 2,4,6- tri-tertiary-amyl-phenol, prepared as set forth above, was added to cc. of a standard reference gasoline having an oxygen stability period of l hours, the stability period was increased to 5% hours.

This compound was also tested as an anti-oxidant for agricultural spray ,oil. Thus, when an oil of this character, having a very pale color and a viscosity of '75 seconds'S. U. V. at F., was

subjected to ultraviolet light for 16 hours under a Westinghouse type S-l lamp at a temperature. of F'., the acid number of the oil increased from 0.02 to 0.30; the oil developed an undesirable yellow color and a distinctly rancid odor. The same 011, inhibited by the addition of 0.1 per cent of 2,4,6-trl-tertiary-amyl-phenol prepared as indicated above, when subjected to the same test, increased in acid number to only 0.12; the odor after test was decidedly improved over that of the uninhibited oil, and substantially no change in color was observed.

While the methods set forth in our previously filed applications are generally applicable for the preparation of 2,4,6-tri-tertiary-amyl-phenol, other methods of synthesizing this compound will readily suggest themselves to those skilled in the art and may be used when desired.

above with respect to various specific illustrative examples, it will be obvious that our invention is not limited to the details of such examples, but may be variously practiced and embodied within the scope of the claim hereinafter made. It will also be understood that our invention is not limited to the use, as antioxidants,- of isolated compounds of the class described, but contemplates also the' use of these compounds in admixture with other compounds of the same class, as well as other materials of an entirely different character, wherever this proves desirable.

What we claim is: 2,4,6-tri-tertiary-amyl-phenol.

DONALD R. STEVENS. WILLIAM A. GRUSE. 

